Factorio Vulcanus Guide: Exact Demolisher Kill Counts, Foundry Smelting Math, and the Cargo Manifest Back to Nauvis

Verified for Factorio Space Age version 2.0. Values may change with future patches.

The first thing Vulcanus takes from you isn’t your health — it’s your production line. Stone piles up before you’ve figured out where to dump it, your smelters stall waiting for calcite, and while you’re troubleshooting a belt loop the Demolisher you’ve been ignoring starts eating your power poles.

That’s the real Vulcanus challenge: two overlapping crises running simultaneously. One requires firepower; the other requires systems thinking. This guide covers both, starting with the numbers that most guides don’t show you.

New to Factorio Space Age? Our Factorio Space Age Beginner’s Guide covers the Nauvis exit checklist, and the planet order guide explains why Vulcanus is the recommended first stop.

Quick Start Checklist

Pack the following cargo before you launch. This is the minimum viable load for a stable first landing.

1. Uranium cannon shells (at least 30): You’ll spend 10–15 per small Demolisher. Bring surplus for medium encounters.
2. Solar panels and accumulators (50 panels, 20 accumulators): Vulcanus solar output is 4× Nauvis. This stack covers your initial factory overnight without a steam setup.
3. Steel plates and concrete (1,200 each): Landing infrastructure consumes both fast [7].
4. Processing units — blue circuits (200 minimum): Foundries are expensive to build. You’ll want to make more than one immediately [6].
5. Repair packs (50+): Demolisher fights damage infrastructure.
6. A tank: Your primary Demolisher killing platform. Uranium cannon shells, not explosive ammo — explained below.
7. Roboport and 20+ construction robots: For rapid deployment and turret repair after fights.
8. Big electric poles and substations: Your grid expands fast once foundries run at scale.
9. Calcite (200 units): Available natively on Vulcanus, but having this in cargo lets you start your first foundry before a mining line is operational.
10. Iron and copper ore (bulk): Until lava casting is online, you need starter ore to bootstrap production.

Vulcanus: Three Biomes, One Set of Rules

Vulcanus has three distinct biomes, and your building options depend on which one you’re standing in [1]:

• Ashlands: Flat volcanic plains. Coal deposits here. Build freely — this is your base zone.
• Lava basins: Rivers and lakes of molten rock. Tungsten ore deposits cluster here, but they sit inside Demolisher territory. You pump lava from these lakes using offshore pumps.
• Mountains: Large volcanic formations with sulfuric acid geysers and calcite deposits. Mine calcite here; build sulfuric acid extraction here.

One hard constraint: lava cannot be transported off-world and cannot be piped across open ashland terrain without proper infrastructure. Your foundries must sit adjacent to — or plumbed directly from — lava basins. Plan your base footprint around that constraint before you place anything.

Vulcanus also lacks water entirely. You produce it via acid neutralization or steam condensation, but there is no natural water source to pipe from [1]. Don’t plan a water-based steam power setup without accounting for this.

Power First: The Solar Math

Solar panels on Vulcanus produce 4× their Nauvis output due to the planet’s proximity to the sun [1]. A panel that outputs 60 kW on Nauvis produces 240 kW here. The landing stack of 50 panels delivers roughly 12 MW continuous — enough to run your first foundries and mining drills without issues.

The complication is the day/night cycle: at 1.5 minutes, nights arrive fast. Accumulators drain quickly. Calculate your overnight load first, then size your accumulator bank to cover it. The recommended 20 accumulators store approximately 200 MJ combined, which sustains moderate factory loads for several in-game nights [9].

For mid-game, transition to sulfuric acid steam turbines: neutralize geyser output to produce 500°C steam and run turbines from that. This provides significantly higher power density in a smaller footprint than expanding a solar farm, which matters once you’re competing for land near lava basins [9].

The Demolisher Combat Equation

This is the section most Vulcanus guides skip. Understanding why a strategy works — or fails — against each tier means you won’t walk away from a medium Demolisher confused about why you spent 40 shells and nothing happened.

All three Demolisher tiers share an identical resistance profile [2]:

• Fire, impact, laser: 100% immune
• Explosion: 99% at body, 60% at head
• Physical: 50% at head, 5 flat + 50% at body
• Electric: 20 flat + 20% at both locations

Lasers do nothing. Explosive grenades and rocket ammo are nearly useless. Fire — including flamethrowers — deals zero damage. Physical damage from cannon shells is your primary tool, and aiming for the head matters because physical resistance there is pure 50%, with no flat component to worry about.

The Regen Gate

What separates Demolishers from every other enemy in Factorio is health regeneration. It’s not a minor annoyance — it’s a hard damage-per-second gate. If your total post-resistance DPS falls below the regen rate, you will never kill the Demolisher regardless of how long you fight [2]:

The right column is the number your weapons must exceed — after all resistance calculations — to do anything productive. This is why weapon choice matters far more than ammunition quantity.

There is also a seismic mechanic worth knowing: the Demolisher’s eruption attack only targets moving creatures, not static structures or players who are standing still [5]. If you stop moving when the eruption warning triggers, the ground explosion misses you entirely.

Small Demolisher (30,000 HP, 2,400/s regen)

The small Demolisher guards the starting tungsten deposit and is the gate between your landing and your first science packs. It’s the one fight you cannot defer.

Method 1 — Tank with uranium cannon shells (recommended early game)

Uranium cannon shells deal physical damage and bypass the Demolisher’s fire and explosion immunities. With tier 4+ physical damage research, each shell delivers 10,000+ effective damage; after the 50% head resistance, roughly 5,000 effective damage lands per shot [8]. To exceed the 2,400/s regen threshold, you only need to fire once every two seconds — well within a tank’s practical rate of fire.

The recommended approach: drive the tank behind the Demolisher (targeting the head from the rear arc), disable auto-robot dispatch so your bots don’t get caught in the fight, and fire continuously. Community testing puts the kill count at approximately 10–15 uranium cannon shells per small Demolisher at mid-level damage research [10]. The variable is upgrade level: go in with at least tier 4 physical damage research or the fight drags significantly.

When NOT to attempt: If you have tier 1 or tier 2 physical damage research only, your effective DPS may hover near the regen threshold, causing a prolonged fight where you burn through ammo for marginal progress. Research more or bring more shells before engaging.

Method 2 — Gun turret array with piercing ammo

Arrange 30–50 gun turrets in a 5×5 or 3×7 grid and lure the Demolisher into the kill zone. The critical timing constraint is the 3-second window: you must kill it before it releases shockwaves that destroy the turret line [6]. This requires overwhelming simultaneous fire, not a drawn-out attrition fight. Load with uranium ammo over red ammo wherever possible for higher physical damage per shot.

Medium Demolisher (100,000 HP, 7,800/s regen)

The medium Demolisher sits deeper in Demolisher territory and requires you to exceed 7,800 post-resistance DPS just to begin making progress. A solo tank is no longer sufficient — cannon shell rate-of-fire can’t sustain that throughput reliably.

Method — Combined arms (turrets + tank)

Set up 40–50 gun turrets with uranium ammo in a pre-built kill corridor and lure the medium Demolisher through. A tank firing from behind adds critical burst DPS in the opening seconds when the turrets are establishing fire. Plan for 30–40% turret losses; pre-position repair packs and construction robots for post-fight recovery.

Alternatively, artillery turrets: community testing indicates approximately 27 artillery turrets in simultaneous-fire range can overcome medium Demolisher regen with damage research [10]. This requires more setup but preserves your gun turret stock.

Big Demolisher (300,000 HP, 24,000/s regen)

The big Demolisher occupies territory far from your starting zone and represents a late-Vulcanus milestone. The 24,000/s regen gate requires sustained DPS that only becomes available with mature research and manufacturing.

A single tank with tier 6+ physical research delivers roughly 10,000 DPS in sustained fire — still below the 24,000 threshold. You need the turret array to provide base damage while the tank adds burst. A functional big Demolisher kill requires 50+ coordinated turrets plus active tank support, with overlapping fire range so all turrets engage simultaneously.

The practical recommendation: don’t fight the big Demolisher until your research tree is mature and you have ammunition manufacturing on Vulcanus itself. It’s not the first thing you clear; it’s the trophy at the end of a complete Vulcanus setup.

Combat Decision Tree

Which weapon approach?

• Tier 4+ physical damage research + small Demolisher → Tank method (~10–15 shells, fastest setup)
• Tier 4+ but fighting medium → Combined turret array (40–50) + tank backup
• Big Demolisher → Full artillery array + mature research; defer until late Vulcanus
• Under tier 4 research → Research more before engaging; guerrilla-mine the border for starter tungsten

Tungsten: Gated Behind Every Kill

Every Demolisher kill drops tungsten ore from its remains [2]. This is your bootstrap supply — you cannot mine tungsten ore directly until you have a big mining drill, and building a big mining drill requires tungsten carbide, which requires tungsten ore. Kill first, mine later.

The full chain:

1. Demolisher kill → tungsten ore (from remains)
2. Tungsten ore + molten iron → tungsten plate (foundry)
3. Tungsten ore + carbon + sulfuric acid → tungsten carbide (foundry or assembling machine)
4. Tungsten carbide → big mining drill (and other advanced components)
5. Big mining drill placed on tungsten deposits → sustainable tungsten ore supply

A single small Demolisher corpse provides enough tungsten ore to build your first big mining drill once you have a running foundry. Don’t sit on the ore — process it immediately into the drill so you can start sustained mining before that patch of bootstrap ore runs out.

The Foundry: Why 50% Productivity Is Bigger Than It Sounds

The foundry is Vulcanus’s core building. Crafting speed 4 (versus an electric furnace’s speed 2) makes it twice as fast per cycle, and the built-in 50% productivity bonus means every cycle produces 1.5× the normal output for the same inputs [3]. Combined, the effective output rate is roughly 3× that of an electric furnace — with no modules installed yet.

The 50% productivity applies even to recipe categories normally excluded from productivity modules [3]. For steel in particular, the compounding is significant: lava casting to molten iron (with productivity) feeds directly into steel casting (with another productivity bonus), eliminating two full stages of ore smelting.

Lava Casting — The Core Recipes

These are the two foundry recipes that eliminate conventional ore mining [3]:

• Molten iron from lava: 500 lava + 1 calcite + 10 stone → 250 molten iron
• Molten copper from lava: 500 lava + 1 calcite + 15 stone → 250 molten copper

Your supply chain becomes: lava lake → offshore pump → pipe → foundry → cast directly to plates, gears, cables, or pipes. Iron ore on Vulcanus is scarce (only in volcanic rock deposits), so lava casting is not an optimization — it’s how the planet is designed to operate.

Once molten metal is in a pipe, route it directly to the next recipe without converting to plates first. Molten copper → copper wire skips the plate step entirely. Molten iron → iron gears skips the plate step too. This “plate-less economy” removes belt congestion and several processing cycles from your production chain [9].

Stone Byproduct — Build Disposal Before You Scale

Every lava casting run outputs stone alongside your metals. At scale, this arrives faster than you can use it. A stalled stone belt halts all foundry output completely. Design all three disposal tiers before turning on your second foundry [9]:

1. Active use: Stone → stone brick → concrete. Use for your own infrastructure. This handles moderate throughput.
2. Compression to landfill: Compact surplus into landfill tiles. Use to fill lava lake edges for building space.
3. Emergency lava dump: Route overflow directly into lava via bulk inserters. In practice, one bulk inserter handles the stone output of roughly 4–6 foundries at full run rate.

The cascade failure pattern is always the same: foundry output fills → stone belt backs up → foundry stalls waiting for stone to clear → everything downstream stops. Pre-built exits prevent this entirely.

Foundry Modules

The foundry has 4 module slots. Stack productivity modules: since the foundry already has crafting speed 4 (twice an electric furnace), you don’t need speed modules to compensate. Productivity 3 modules push resource efficiency further — especially valuable for tungsten plate production where ore availability is limited before big drills are fully online.

The Big Mining Drill

Once you have enough tungsten carbide, the big mining drill replaces electric mining drills for all ore extraction [4].

The 50% resource drain reduction is the stat that matters most long-term: your ore deposits last twice as long at Normal quality, and at higher quality tiers the drain drops further — to 8% at Legendary [4]. A single big mining drill covers roughly 6× the surface area of a standard electric drill, replacing several machines at once.

For placement: position drills as close to deposit centres as possible to maximise yield before depletion. On tungsten deposits specifically, place them as soon as the Demolisher territory is cleared — earlier mining means more ore before the patch thins.

Calcite Economy

Calcite is the throughput bottleneck most players hit at mid-scale Vulcanus. Every lava casting cycle consumes 1 calcite per foundry per cycle [3]. As your foundry count grows, your calcite supply must grow with it.

Mine calcite from mountain deposits using standard electric mining drills or big mining drills (once available). In practice, one big mining drill on a calcite deposit sustainably supplies 6–8 foundries running at moderate throughput. At 15–20+ foundries, run two or three dedicated drills on separate mountain deposits.

Calcite can also be shipped to other planets once you’ve transported foundries — it becomes a cross-planetary commodity for any world where you deploy foundry production [3].

Recommended Base Progression

Vulcanus rewards a linear unlock sequence over sprawling expansion. The common failure is chasing production volume before establishing stable disposal and power [9]:

Quality Crafting on Vulcanus

Vulcanus is the best early-game planet for quality crafting experiments. Three reasons:

1. The foundry’s 4 module slots accommodate quality + productivity combinations without sacrificing output.
2. Tungsten carbide is a prerequisite for high-tier quality recipes on later planets (Fulgora, Aquilo) — producing quality tungsten carbide here front-loads your options.
3. No biter evolution or nest respawning means quality experiments run uninterrupted indefinitely.

If you have quality modules available, run a small parallel foundry line in quality mode. An uncommon foundry (crafting speed 5.2) or rare foundry (crafting speed 6.4) versus the Normal tier’s 4.0 represents a meaningful throughput gain — especially when exported back to Nauvis as part of your return cargo [3].

Return Cargo Manifest: What to Pack for Nauvis

The return trip is where most players under-pack. The Vulcanus-exclusive buildings are more valuable than any raw material you can bring back.

One item to leave behind: lava. It cannot be transported and has no off-world form. All lava-based production is permanently planetary.

Fulgora is the most common second destination after Vulcanus. See our Factorio Fulgora Guide for the electricity loop, recycler economy, and lightning defence before you land.

Player Profiles

Frequently Asked Questions

Can I get tungsten ore without killing a Demolisher?

Yes, but not sustainably. You can gather small quantities by mining volcanic rocks manually or sending construction robots to pick up exposed surface nodes at the edges of Demolisher territory — the Demolisher won’t aggro until you build inside its territory. This guerrilla approach gives enough ore to bootstrap a first foundry and start the tungsten chain while delaying the fight. Once you have the chain running and your research is ready, clear the territory properly.

Why isn’t my artillery damaging the Demolisher?

Artillery shells are explosive damage type. The Demolisher’s body has 99% explosion resistance — essentially immune — and even the head only passes 40% of explosive damage [2]. Combined with the regen rate, artillery alone rarely delivers enough DPS unless you’re running 10+ turrets simultaneously at close range. Switch to uranium cannon shells (physical type) for the main damage deal and reserve artillery for long-range territory deterrence.

How much calcite do I actually need per foundry?

Each molten iron casting cycle (500 lava → 250 molten iron) consumes 1 calcite [3]. At five foundries running simultaneously on lava casting, that’s 5 calcite per cycle across your production. In practice, one big mining drill on a calcite deposit comfortably supplies 6–8 foundries at moderate throughput. Add a second drill when you hit 15–20 foundries.

What’s the fastest path to metallurgic science packs?

Kill the starting small Demolisher → gather tungsten ore from remains → produce tungsten carbide in foundry → produce science packs. With proper prep (arriving with calcite and blue circuits in cargo), you can be producing metallurgic science packs within 30–60 minutes of landing. The gate is always tungsten carbide; prioritise that chain above all else in the first session.

Do Demolisher territories regenerate after I clear them?

No. Each Demolisher death is permanent [1][5]. The territory remains cleared indefinitely; no new Demolisher spawns to replace it. Vulcanus gets progressively safer as you expand outward. Clear a territory once, own it forever — there’s no biter-equivalent evolution mechanic to worry about.

Should I build foundries on other planets too?

Yes. Foundries accept recipes from any planet once transported. The 50% productivity bonus applies everywhere, making them the superior smelting building regardless of location [3]. Exporting foundries back to Nauvis and to later planets (Fulgora, Aquilo) is one of the highest-ROI actions from the Vulcanus trip. Pack as many as your cargo allows on the return flight.

Sources

1. Vulcanus — Factorio Wiki
2. Demolisher — Factorio Wiki
3. Foundry — Factorio Wiki
4. Big Mining Drill — Factorio Wiki
5. Friday Facts #429 — Vulcanus Demolisher Enemies. Factorio Official Blog
6. Complete Vulcanus Guide in Factorio 2.0. PrimaGames
7. Factorio Space Age — Vulcanus Beginners Guide. number13.de
8. Factorio — Early Vulcanus. Leo’s Life
9. Vulcanus Strategy Guide. factorio-wiki.pages.dev
10. Artillery vs Uranium Shells DPS Analysis. Steam Community

Michael R.

I've been playing video games for over 20 years, spanning everything from early PC titles to modern open-world games. I started Switchblade Gaming to publish the kind of accurate, well-researched guides I always wanted to find — built on primary sources, tested in-game, and kept up to date after patches. I currently focus on Minecraft and Pokémon GO.